Apparatus for splitting slate blocks and the like.



C. SUDRE.

APPARATUS FOB SPLITTING SLATE BLOCKS AND THE LIKE,

APPLICATION FILED APB.17, 1912.

1 ,094, 1 77, Patented Apr. 21, 1914.

2 SHEETSSHBET 1.

44% W aw Mm.

COLUMBIA PLANDGRAPH c0., WASHINGTON. D c

APPLICATION FILED APR. 1'], 1912.

Patented Apr. 21, 1914.

2 SHEETS-SHEET 2.

- COLUMBIA PLANOORAPH c0.. WASHINGTON. n. c.

CHARLES sunnn, or RENAZE, FRANCE.

APPARATUS FOR SPLITTING- SLATE BLOCKS AND THE LIKE.

Specification of Letters Patent.

Patented Apr. 21, 1914:.

Application filed April 17, 1912. Serial No. 691,280.

To all whom it may concern:

Be it known that I, CHARLES SUDRE, a citizen of the Republic of France,residing at Renaz, Department of Mayenne, in France, have invented newand useful Improvements in Apparatus for Splitting Slate Blocks and thelike, of which the following is a full, clear, and exact description.

This invention relates to an improved appzliratus for splitting slateblocks and the li to.

Various methods and apparatus for the splitting of slate by mechanicalmeans are already known, particularly those in which a block of slate issplit by a knife or thin blade in such a way that it is first dividedinto two halves and then each half again split by itself, and so onuntil two pieces of slate are obtained each of the same thickness.According to another method the block is split simultaneously into agreat number of pieces by means of a corresponding number of knives.These existing processes and apparatus have however the defeet that theoutput in consequence of the excessive waste is very low particularlyowing to the fact that the resilience or elasticity of the slate is nottaken into account.

The apparatus which forms the object of this application is based upon adiiferent method.

Splitting by hand has shown that the individual sheets of slate haveundoubtedly a small degree of elasticity and only break when they aretoo much bent during splitting that they go beyond their angle offlexibility, that is to say, if the block of slate is subjected to sucha strain that the breaking point is exceeded. The edge of the splittingknife should never show a greater angle than the double angle offlexibility of the slate. If this double angle is exceeded then theslate breaks while being split. The same thing occurs if the splittingedge is applied in too greatalengthto thesheet of slate as there is thena risk of cutting the splitting surface. Finally the stone may also bedefective so that rigid, that is, non-flexible knives produce anirregular split. By the application of this method these drawbacks arediminished and a much larger number of regular sheets or slabs of slateare produced. It consists of splitting up a block of slate in oneoperation into 2, 4, 8, 16, 32 etcetera sheets according to thethickness of the block and of the sheets or slabs it is desired toproduce. This is effected by groovmg the stone on two opposite sides bymeans of spikes or small blades carried by suitable supports and it isthen split completely from the top that is from a third side. Theoperation is effected by means of several thin blades, inclined andarranged in steps. The operation is commenced at the center of the blockby using one knife the cutting edge of which should not be at a greaterangle than the double angle of flexibility of the slate. The side knives2, 4:, 8 etc. are however placed in steps the one above the others. Theyare also thinner and their cutting edge in no case exceeds the singleangle of flexibility of the slate. In consequence of this, the slatewhen being split is not subjected to a strain in excess of the breakingpoint, the splitting is easily effected, and as much waste is preventedas possible.

The apparatus for carrying out the invention consists essentially of ahorizontal table on which the block of slate to be split rests on itsunder side, a couple of resilient supports to seize and hold the stoneon two sides parallel to the plane of cleavage, a pair of lateralsupports carrying spikes or small blades and a frame to carry thesplitting knives, supported by a slide which can move up and downvertical rods. The knives which penetrate the block of slate areintended together with the lateral small blades, to fix the direction inwhich the block of slate is to be split and should correspond with this.By means of the grooves the stone is arranged in sucha way as tofacilitate the splitting, and shape it more regularly. Owing to theflexible knives being arranged obliquely to the stone any cutting of thesplitting surface is avoided, and the flexible. blade follows thesplitting surface exactly. The arrangement of the knives in rows, oneabove the other is intended to effect the same purpose of regularsplitting with small waste. The bottom knife has a cutting edge, theangle of which is smaller than the double angle of flexibilitiy of theslate, while in the top knives the cutting edge must be smaller than thesingle angle of flexibility. The number of rows in which the knives arearranged may be varied according to the number of sheets or slabs to becut out of a block. For instance, if 16 sheets are to be produced fromone block, there would be four rows of knives, the

frames independent of each other.

number being double in each consecutive row. The separate rows of knivesmay also be arranged on a single frame or on several They may also beall actuated together or gradually in succession and in any manner, thatmay be desired.

'The accompanying drawing shows by way of example a machine forsplitting a slate block into four pieces.

Figures 1, 2 and 3 show the apparatus in elevation, side elevation, andplan partly in section. Figs. '4 and5 show an elevation and plan of theframe carrying the knives. Fig. 6 shows a front elevation and sideelevation of the grooving arrangement. Fig. 7 shows a rider placed onthe knives. Fig. 8 shows a bar of the grating forming the table. Fig. 9shows in plan the frame supporting the guide rod for the rider of Fig.7.

The frame 1 carries a table 2, on which the block of slate 3 rests.Underneath the table is a girder or beam 4 which is provided withbearings 5, for the screw spindles 6 and 7 which are actuated by cranks8. Each of the spindles 6 and 7 carries a nut 9 and 10 to whichresilient supports 13, 14 are attached by the rods 11, 12. The frontsurface of these supports is provided with a covering 15 of rubber orother suitable material so that the block of slate 3 is maintainedbetween them.

The inner surfaces of the supports 13, 14 are curved to enable the blockof slate 3 to be kept fixed as well as possible. a At right angles tothe beam 4 a second beam 16 is mounted under the table and provided withtwo bearings 17, 18 for the screw spindles 19, 20 which are driven bycranks 21. Nuts 22, 23'are mounted on these spindles, and transmit theirmotion to the supports 26, 27 connected with them by rods 24, 25. Thesesupports are provided with small blades or spikes which are arranged asshown in Fig. 6.

The four standards 29 serve to guide the slide which carries thesplitting knives. This slide is preferably made of two frames 30, 31connected with each other by sleeves 32. The weight of the slide iscounterbalanced in any suitable manner, so that it can move up and downeasily. A cam 33 is mounted on the rod 34 actuated by the crank 35 andengages projection 36 on the slide. This projection is affixed to thetop of the frame 31. The slide is pressed down by turning the crank 35.

A frame carrying the knives is affixed by pins which pass through theopenings 39, to the bottom 30 of the slide. This frame consists of twolongitudinal sides 37, which are connected with each other by crosspieces 38. V

Square rods 44 pass through the cross pieces 38 and are held firmly inposition by nuts 45. Both rods 44 are provided at the ends with twoholders 42, 43 between which the knives 40, 41 are clamped so that theyalways stand vertically and the tension can be increased or diminishedby tightening or loosening the nut 45. The rods 44 are arranged in thecross pieces 42, 43 so that they incline to the horizontal (Fig. 4).

If the apparatus is provided with two rows of knives they are dividedinto uneven numbers as follows I--O1]G knife 40 is the thicker viz:about 1 millimeter thick and the angle of its cutting edge is smallerthan that of the double angle of flexibility of the slate. The twoknives 41 are thinner, 0., only about 9; millimeter thick and the angleof their cutting edge is smaller than the single angle of flexibility ofthe slate. The knives 41 are arranged in an upper row, which is somecentimeters higher than the lower row containing the thicker knife sothat this has penetrated the slate block before the second row of knivesbegins its action. As the knives are only about two centimeters wide andare arranged in different rows the incision made by the lower knives hasthe tendency to close again during the action of the upper blades sothat the fiexion of the slate can act on both sides of the knife. Bythis arrangement of the knives several sheets of slate of any desiredthickness can be split off in one operation without the breaking pointof the slate i. 0., the angle of flexibility being exceeded waste beingthus to a great extent avoided. If it is desired to fill up theintervening space arising from the passing through of the knife, a sheetof rubber or other flexible material can be placed into the split behindthe knives. In order to prevent the knives from springing or becomingwarped, a. rider 46 placed upon the knives is used during the splitting.This rider consists of a piece of metal in which grooves 47, 48 havebeen cut to receive the knives 40-41.

The grooves 48 are intended to receive the thicker knives 40 whichproject from them only about 2 millimeters, while the grooves 47 must becut deeper in consequence of the position of the thin knives beinghigher. The rider 46 can be pushed to and fro on an adjustable guide rod49 while its head 50 encircles the guide rod 49 which rests on a lightframe 51, which slides to and fro on the guide rod 29. In consequence ofthis arrangement the rider will then occupy the position shown in Fig. 7when the knives begin to penetrate the slates and will remain in thesame posit-ion during the complete operation.

In the same way the table 2 is provided with blocks 52 to receive theknives when they have reached the underside of the block of slate. Theblocks 52 are provided with grooves 53 (Fig. 8) or may be in the form ofa grating 54. The stone to be split rests on the bars of this gratingwhich serves as a bearing for the stone and at the same time receivesthe knives which have split the latter.

The apparatus works as follows :-After the requisite number of kniveshave been inserted and their distance from each other adjusted accordingto the thickness of the sheets or slabs of'slate which have to be splitoff, the block of slate is put upon the table 2, and maintained inposition between the supports 13, 14. Then the supports 26, 27 carryingthe spikes 28 for making the grooves and preparing the stone forsplitting at the desired points are firmly pressed in and are afterwardremoved again, in order to allow the cutting knives to go through theslate. The slide 32 is then pressed down and the bottom knife 40 strikesfirst upon the block and commences to split it when the rider 46 remainsat its place. The top knives 41 then commence to split the second seriesof slate slabs. When the splitting is finished the supports 13, 14 arereleased, the slide drawn up, the split block taken out, and replaced bya fresh one. Moreover, with the same apparatus a block of slate can besplit beginning at one end. In this case a single knife only 2/10millimeters thick, is used, one of the supports 13, 14 remainspermanently fixed, while the other serves to hold and displace the blockafter each splitting and to remove the piece split off.

I claim 1. Apparatus for splitting blocks of slate or the like into two,four, eight, sixteen etc. numbers of slabs or sheets comprising incombination a table for supporting the block provided with a groovedsurface for receiving the splitting knives, two side supports to seizeand hold the block on two sides parallel to the plan of cleavage,actuating rods attached to said supports, a cover of resilient materialfixed upon said supports, two supports arranged on opposite sides of theblock, actuating rods attached to said second supports, grooving bladescarried by said rods, means for driving said actuating rods, a slidingcarrier for splitting knives, a number of thin inclined flexible knivesarranged in rows for splitting the block, a frame, an adjustable rod ofsaid frame, a rider on said rod to receive the knives, and means foractuating the splitting knives substantially as above described and forthe purpose set forth.

2. Apparatus for splitting blocks of slate or the like into two, four,eight, sixteen etc. numbers of slabs or sheets comprising in combinationa table for supporting the block, said table having grooves forreceiving the splitting knives, two side supports for holding the block,two supports with grooving blades, means for actuating the saidsupports, a sliding carrier for splitting knives, a number of splittingknives arranged at an inclination and mounted on rows one above theother, the lower knife bein thicker and having its cutting edge smal erthan the double angle of flexibility of the slate, the other knivesbeing thinner and having their cutting edge smaller than the singleangle of flexibility of the slate, a frame with adjustable rod; a rideron said rod to receive the knives and grooved or recessed to correspondwith the rows of splitting knives, and means for actuating the splittingknives substantially as above described and for the purpose set forth.

3. Apparatus for splitting blocks of slate or the like into two, four,eight, sixteen etc. numbers of slabs or sheets comprising in combinationa table for supporting the block, said table having grooves forreceiving the splitting knives, two side supports for holding the block,a cover of resilient material for said side supports, two supports withgrooving blades, means for actuating the said supports, a slidingcarrier for splitting knives, a number of splitting knives arranged atan inclination and mounted on rows one above the other, the lower knifebeing thicker and having its cutting edge smaller than the double angleof flexibility of the slate, the other knives being thinner and havingtheir cutting edge smaller than the single angle of flexibility of theslate, a frame with adjustable rod; a rider on said rod to receive theknives and grooved or recessed to correspond with the rows of splittingknives, and means for actuating the splitting knives substantially asabove described and for the purpose set forth.

CHARLES SUDRE. Witnesses:

H. O. Coxn, VIoToR MARnNDowsxI.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

